Vehicle differentials include gearing to allow the wheels of the vehicle to rotate differently for purposes such as anti-slip, traction control, oversteer, and understeer. One portion of the differential may house pinion gears on one or more shafts. The pinion gears can thereby maintain a location relative to cooperating side gears.
Some differentials may comprise four pinions. Some differentials of this type have required that the housing surrounding four inner pinions be split down the middle in order to mount the pinion shafts. One example having this design overlaps cross shafts with central notches. The machining requirements are high because the housing must mate along a plane, the cross shaft notches must mate, and the housing is typically modified on one or both halves to receive the cross shafts. The design is also bulky and heavy because the housing must have means to lock the halves together.
Other designs for four pinion differentials have a one-piece housing and some combination of stub shafts and cross shaft. The machining requirements are also high for these prior art stub shaft designs because of the use of threaded fasteners in addition to machining for alignment of the stubs and cross shaft. The design may also include retaining plates, thereby increasing the number of toleranced parts. The designs are bulky and heavy because the threaded areas require additional materials for rigidity and the housing requires sufficient means to accept the retaining plates and or threaded members.